Two-cycle multiple cylinder diesel



June 20, 1950 c, cu s 2,511,905

TWO-CYCLE MULTIPLE CYLINDER DIESEL ENGINE Filed Feb. 12, 1946 v INVENTOR.

('iidF/ff 61 mm? Patented June 20, 1950 'rwo-oYoLE MULTIPLE u ENGINE o-FFI EI LI DER E EP Charles iGQClurtis, New York, N. Y. l Application February 12, 1946, SeriarNo 647,667

The present invention rovides improvements wherein air provided for scavenging and charging a two cycle internal combustion engine is prevented from being contaminated by oil particles or vapor in sludge which runs down from the cylinders into an air chamber into which the bottom of the engine cylinders open. By the present construction, the air for charging and scavenging is free from sludge oil contamination and the air pressure at the inlet ports is maintained practically constant.

In order to keep the engine as short as possible and to have the cylinders of as small bore, compared with the stroke, as possible, I prefer to build the engine cylinders 2 in the V form with crossheads 4 and with short pistons 5. There are a plurality of these cylinders, pistons and crossheads, and a plurality of connecting rods 8, connecting the several crossheads 4 with cranks ID on a common crank-shaft. In the usual type of crosshead engine, using a diaphragm and short piston, the cylinder wall and the inlet ports project into a chamber which is fed with scavenging air, and which also acts as an equalizing chamber so that when the piston in its down stroke forces the contents of e the cylinder into this chamber this air is conveyed to the other cylinders, the pistons of which are moving upward, so that there is comparatively little rise of pressure in the scavenging chamber. Similarly, when the piston is rising in one cylinder and tending to produce a lower air pressure in the chamber, this is more or less neutralized by the downward movement of one or more of the other pistons.

Instead of using a single chamber for equalizing the pressure and for conveying the scavenging air to the inlet ports 24, I use two chambers with bottom walls or diaphragms which slope downwardly toward each side of the engine. One of these chambers is a lower chamber 25 into which the cylinder walls project and which is of suflicient capacity in cooperation with the other cylinders to avoid too great a fluctuation of pressure, and an upper scavenging chamber 26 feeding the inlet ports 24, which is entirely independent of the lower chamber. In the usual arrangement, parts of the lower chamber are subject to blasts of air moving at high velocity and as these parts are covered with more or less sludge oil dripping down from the cylinders, the oil is picked 4 Claims. (01. 123-65) up by the blasts of air and carried into the inlet ports 24. In other words, the scavenging air is contaminated by an oil vapor or particles coming from the sludge. In my arrangement, the scavenging air is entirely free from such oil contamination and the scavenging air pressure at the inlet ports is maintained practically constant.

In order to avoid an accumulation of hot gas in the lower chamber, I provide a close fitting adjustable diaphragm l2 made in segments where the piston rod passes through the partition 28 between the chamber and the crankcase. This takes the place of ordinary packing. The adjustable plates l2 fit closely to the piston rod with a slight clearance and permit a certain amount of leakage from the lower chamber into the crankcase. This also avoids the necessity of having a gas-tight packing at this point and keeping it in order.

The piston rods 1 may be guided by any suitable form of crosshead, as indicated by the numeral 4, and there may be any suitable form of connection between the piston rod and the crosshead as pin l5 which passes through a hole in the lower end of the piston rod and holds the lower end of the piston rod in a suitable socket or a seat in the crosshead.

What is claimed is:

1. A V type internal combustion engine comprising cylinders in V arrangement provided with uniiiow scavenging, crossheads and connecting rods operating on a common crankshaft, said cylinders having short pistons and piston rods projecting through diaphragms and terminating at said crossheads, the cylinders projecting into a space or pumping chamber common to several cylinders so that the sludge from both cylinders will be carried down along the inclined diaphragm on each side of the V.

2. A V type two-cycle internal combustion engine comprising cylinders in V arrangement provided with uniflow scavenging, crossheads and connecting rods operating on a common crankshaft, short pistons and piston rods connecting through diaphragms with said cross heads below the diaphragms, and a scavenging chamber common to both sets of cylinders and placed above the pumping chamber so as to keep the scavenging air free from all contamination and at substantially constant pressure.

3. In a two-cycle uniflow internai combustion engine, having power cylinders in V arrange ment projecting into a pumping chamber common to several cylinders, short pistons and piston rods connecting through diaphragms with crossheads below the diaphragms, an independent scavenging chamber placed above the pumping chamber whereby contamination of the scavenging air by oil picked up in the pumping chamber is eliminated.

4. A two-cycle uniflow internal combustion engine having power cylinders in a V arrangement, projecting into a pumping chamber common to and connecting opposite cylinders,.short pistons and piston rods connecting through diaphragms with crossheads below the diaphragms, and a scavenging chamber common to both sets of cylinders and placed above the pumping chamber so as to keep the scavenging air free from oil contamination and substantially at constant pressure.

CHARLES G. CURTIS.

, REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 460,319 Courtwright Sept. 29, 1891 813,746 Shanck Feb. 27, 1906 1,237,373 Nordberg Aug. 21, 1917 1,390,541 Randall Sept. 13, 1921 1,405,403 Everett et 'al Feb. 7, 1922 1,410,019 Krause Mar. 21, 1922 1,415,858 .Barrett May 16, 1922 1,460,728 Neldner July 3, 1923 1,540,286 Roberts June 2, 1925 1 1,576,830 Jordan et a1 Mar. 16, 1926 2,064,913 Hedges Dec. 22, 1936 2,113,480 Kadenacy Apr. 5, 1938 3 2,131,958 Kadenacy Oct. 4, 1938 2,220,173 Olsson Nov. 5, 1940 2,376,233 Curtis May 15, 1945 FOREIGN PATENTS Number Country Date 330,993 Germany of 1920 

